/* ============================================
   許彧銘 作品集 — 共用設計系統
   溫潤編輯誌風格 (Editorial / Warm Paper)
   ============================================ */

:root{
  --paper:#f6f1e7;
  --paper-2:#efe7d6;
  --paper-3:#e8dec8;
  --ink:#1d1a15;
  --ink-soft:#5b5346;
  --ink-faint:#6b6255; /* 對比 ≥4.5:1(含 --paper-2 卡片底色),調淺前先驗算 */
  --accent:#b03a22;    /* 同上:當文字色時需在 --paper-2 上 ≥4.5:1 */
  --accent-deep:#8f2d18;
  --line:rgba(29,26,21,0.14);
  --line-soft:rgba(29,26,21,0.08);
  --serif:"Noto Serif TC","Fraunces",serif;
  --display:"Fraunces","Noto Serif TC",serif;
  --sans:"Noto Sans TC",sans-serif;
  --mono:"Space Mono",monospace;
  --maxw:1180px;
}

*{margin:0;padding:0;box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  font-weight:300;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
  position:relative;
}
/* 紙張顆粒紋理 */
body::before{
  content:"";
  position:fixed;inset:0;
  pointer-events:none;z-index:9999;
  opacity:0.04;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}
::selection{background:var(--accent);color:var(--paper);}

a{color:inherit;}
img{max-width:100%;display:block;}

.wrap{max-width:var(--maxw);margin:0 auto;padding:0 40px;}

/* ── 導覽列 ── */
nav{
  position:fixed;top:0;left:0;right:0;z-index:100;
  display:flex;align-items:center;justify-content:space-between;
  padding:22px 40px;
  transition:background .4s ease, border-color .4s ease, padding .4s ease;
  border-bottom:1px solid transparent;
}
nav.scrolled{
  background:rgba(246,241,231,0.82);
  backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line-soft);
  padding:14px 40px;
}
.brand{font-family:var(--serif);font-weight:700;font-size:1.15rem;letter-spacing:.04em;text-decoration:none;}
.brand .dot{color:var(--accent);}
.nav-links{display:flex;gap:34px;align-items:center;}
.nav-links a{
  font-family:var(--mono);font-size:.74rem;letter-spacing:.12em;
  text-transform:uppercase;color:var(--ink-soft);text-decoration:none;
  position:relative;transition:color .3s;
}
.nav-links a::after{
  content:"";position:absolute;left:0;bottom:-4px;width:0;height:1px;
  background:var(--accent);transition:width .35s ease;
}
.nav-links a:hover{color:var(--accent);}
.nav-links a:hover::after{width:100%;}
.nav-links a.active{color:var(--accent);}

/* 漢堡按鈕(平時隱藏,手機才出現) */
.nav-toggle{display:none;flex-direction:column;justify-content:center;gap:5px;
  width:40px;height:40px;padding:9px 8px;background:none;border:none;cursor:pointer;}
.nav-toggle span{display:block;height:2px;width:100%;background:var(--ink);border-radius:2px;
  transition:transform .3s ease, opacity .25s ease;}
nav.menu-open .nav-toggle span:nth-child(1){transform:translateY(7px) rotate(45deg);}
nav.menu-open .nav-toggle span:nth-child(2){opacity:0;}
nav.menu-open .nav-toggle span:nth-child(3){transform:translateY(-7px) rotate(-45deg);}

/* ── 區段標題 ── */
.section-head{
  display:flex;align-items:baseline;gap:20px;margin-bottom:56px;
}
.section-head .num{font-family:var(--mono);font-size:.8rem;color:var(--accent);letter-spacing:.1em;}
.section-head h2{
  font-family:var(--serif);font-weight:500;font-size:clamp(1.7rem,4vw,2.7rem);
  letter-spacing:.02em;
}
.section-head .rule{flex:1;height:1px;background:var(--line);align-self:center;}

/* ── 返回連結(作品內頁與子頁共用) ── */
.back-link{
  font-family:var(--mono);font-size:.74rem;letter-spacing:.1em;color:var(--ink-faint);
  text-decoration:none;display:inline-flex;align-items:center;gap:9px;margin-bottom:40px;
  transition:gap .3s,color .3s;
}
.back-link:hover{color:var(--accent);gap:14px;}

/* ── 子頁版頭(works / about 共用;.tight 收窄下留白) ── */
.page-hero{padding:160px 0 40px;}
.page-hero.tight{padding-bottom:20px;}
.page-eyebrow{
  font-family:var(--mono);font-size:.78rem;letter-spacing:.28em;text-transform:uppercase;
  color:var(--accent);margin-bottom:22px;display:flex;align-items:center;gap:14px;
}
.page-eyebrow::before{content:"";width:40px;height:1px;background:var(--accent);}
.page-title{
  font-family:var(--display);font-weight:300;
  font-size:clamp(3rem,9vw,7rem);line-height:.95;letter-spacing:-.01em;
}
.page-title.has-lead{margin-bottom:26px;}
.page-lead{
  font-family:var(--serif);font-weight:300;max-width:640px;
  font-size:clamp(1.1rem,2.2vw,1.45rem);line-height:1.7;color:var(--ink-soft);
}

/* ── 通用按鈕 ── */
.btn{
  display:inline-flex;align-items:center;gap:12px;
  font-family:var(--mono);font-size:.8rem;letter-spacing:.08em;
  text-decoration:none;cursor:pointer;border:none;
  transition:gap .3s, background .3s, color .3s, opacity .3s;
}
.btn-primary{
  background:var(--accent);color:var(--paper);
  padding:16px 30px;border-radius:6px;
}
.btn-primary:hover{background:var(--accent-deep);gap:18px;}
.btn-ghost{
  color:var(--ink);border:1px solid var(--line);
  padding:15px 28px;border-radius:6px;
}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent);gap:18px;}
.btn .ar{transition:transform .3s;}
.btn:hover .ar{transform:translateX(3px);}

/* ── 進場動畫 ── */
.reveal{opacity:0;transform:translateY(28px);transition:opacity .9s cubic-bezier(.16,1,.3,1),transform .9s cubic-bezier(.16,1,.3,1);}
.reveal.in{opacity:1;transform:none;}
.hero-anim{opacity:0;transform:translateY(34px);animation:rise 1.1s cubic-bezier(.16,1,.3,1) forwards;}
.d1{animation-delay:.1s;}.d2{animation-delay:.26s;}.d3{animation-delay:.42s;}.d4{animation-delay:.58s;}.d5{animation-delay:.74s;}
@keyframes rise{to{opacity:1;transform:none;}}

/* ── 頁尾 ── */
footer{
  padding:110px 0 56px;border-top:1px solid var(--line);
  background:linear-gradient(180deg,transparent,rgba(29,26,21,0.03));
  margin-top:120px;
}
.contact-big{
  font-family:var(--display);font-weight:300;
  font-size:clamp(2.2rem,7vw,5rem);line-height:1.05;letter-spacing:-.01em;margin-bottom:42px;
}
.contact-big em{font-style:italic;color:var(--accent);}
.contact-links{display:flex;flex-wrap:wrap;gap:14px 44px;margin-bottom:72px;}
.contact-links a{
  font-family:var(--serif);font-size:1.2rem;color:var(--ink);text-decoration:none;
  display:flex;align-items:center;gap:12px;transition:color .3s,gap .3s;
}
.contact-links a .ar{color:var(--accent);transition:transform .3s;}
.contact-links a:hover{color:var(--accent);gap:18px;}
.contact-links a:hover .ar{transform:translateX(4px);}
.foot-base{display:flex;justify-content:space-between;flex-wrap:wrap;gap:14px;
  font-family:var(--mono);font-size:.7rem;letter-spacing:.08em;color:var(--ink-faint);}

/* ── 減少動態效果:尊重使用者系統設定 ── */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{
    animation-duration:.01ms !important;
    animation-delay:0s !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
    transition-delay:0s !important;
  }
}

/* ── RWD ── */
@media(max-width:860px){
  .wrap{padding:0 24px;}
  nav{padding:18px 24px;}nav.scrolled{padding:12px 24px;}
  .nav-links{gap:20px;}
}
@media(max-width:560px){
  .nav-toggle{display:flex;}
  .nav-links{
    position:absolute;top:100%;left:0;right:0;
    flex-direction:column;align-items:stretch;gap:0;
    background:rgba(246,241,231,0.98);backdrop-filter:blur(12px);
    border-bottom:1px solid var(--line-soft);
    padding:0 24px;
    max-height:0;overflow:hidden;opacity:0;pointer-events:none;
    transition:max-height .35s ease,opacity .3s ease,padding .35s ease;
  }
  nav.menu-open .nav-links{max-height:340px;opacity:1;pointer-events:auto;padding:8px 24px 20px;}
  .nav-links a{padding:14px 0;font-size:.82rem;border-bottom:1px solid var(--line-soft);}
  .nav-links a:last-child{border-bottom:none;}
  .nav-links a::after{display:none;}
  .nav-links a.cta{color:var(--accent);}
}